The Jaffa are humans, and, as a race, have been used by the Goa'uld for thousands of years, to provide warriors, priests and slaves. Until the ritual of prim'ta, which is when the young Jaffa receives a larval Goa'uld symbiote, they are, to all intents and purposes, normal humans, with the exception of a pouch in their stomachs, in which the Goa'uld will be incubated.

Once they receive their symbiote, they are dependant on the larval Goa'uld for health and strength, and, if the larva dies, the Jaffa generally dies shortly after as well.

The Jaffa are easily identifiable by the marking on their forehead, which is a tattoo of the symbol for the Goa'uld which they serve. Due to the regenerative abilities of the symbiote they carry, the Jaffa are long-lived, generally living for 120-150 years.

The Jaffa are raised in servitude to the Goa'uld, and they tend to view their masters as gods, and not to be crossed. Not all Jaffa are enemies of earth, however: the rebel Jaffa, led by Bra'tac and Teal'c, are Earth's allies, and their inherent courage means that they are unafraid to go up against those who enslaved them in the past.